Namaqua chameleons (Chamaeleo namaquensis) are the largest chameleon species found in South Africa. Namaqua chameleons are ground living lizards that can reach up to 25 inches in size. They have large dorsal spines and a pointed casque on the back of their head, but do not have a neck flap. They also have a short tail in comparison to their body, which is an adaptation for their terrestial habitat.
Chameleons are heliothermic, which means they get their heat directly from the suns' rays. The basic form of temperature the namaqua chameleons use is simply moving into the sunlight to warm up, known as basking. They position their body to be on the side of the sun, exposing the maximum amount of surface area to the sun. They also move into the shade to cool down. All chameleons also have hinged ribs, which allow them to flatten their body , increasing the surface area of the side exposed to the heat source. Another form of temperature control is changing their rate of their heart beat. In order to warm up, namaqua chameleons' heart beat significantly speeds up, transferring heat to their cool core.
To help with thermoregulation, the Namaqua chameleon also has many adaptations to cope with the desert conditions. This species of chameleons also dig holes in the sand to reach the cooler sand beneath for thermoregulation. To prevent them from overheating, the Namaqua chameleons will also stand on straightened legs to lift their body off the hot sand, a behaviour known as 'stilting.'
Namaqua chameleons also use their ability to change colour to help with thermoregulation, as they turn black in the early cool morning to absorb heat more efficiently. During the heat of the day, the Namaqua chameleon turns a lighter grey colour to reflect light and cool down. This also helps these chameleons hide from predators as it acts as camouflage.